Start by cutting the chicken into one-inch pieces. Place the chicken in a shallow dish.

Next, let's make the yakitori sauce. In a small saucepan, combine the soy sauce or tamari, mirin, sake or sherry, brown sugar, garlic, and ginger. Heat the sauce over medium heat until it begins to simmer.

Continue simmering the sauce for a few minutes until it thickens slightly. Remember to reserve a portion of the sauce for serving later.

Pour the sauce over the chicken, making sure each piece is well coated. Cover the dish and refrigerate for at least one hour to allow the flavors to meld together.

If you are using wooden or bamboo skewers, soak them in water for about 30 minutes to prevent them from burning during grilling.

Now it's time to grill or broil the chicken. Preheat your grill or broiler to medium-high heat. Thread the marinated chicken onto the skewers.

Grill or broil the chicken skewers for about 4-5 minutes per side, or until the chicken is cooked through and lightly charred. Cooking times may vary depending on the size of the chicken pieces.

Once the chicken is cooked, remove it from the grill or broiler. Drizzle some of the reserved sauce over the finished skewers for an extra burst of flavor.

For the finishing touch, garnish the chicken yakitori skewers with sliced scallions. This adds a refreshing and aromatic element to the dish.